build_image: add padding to match partition size

For some partition sizes, we currently build an image that's 1-2
blocks smaller than the actual partition, which causes fs_mgr to
not find metadata. This change adds padding to FEC metadata that
correctly positions the metadata header at the end.

Bug: 28865197
Change-Id: Ie0e044715a9c5ae8ba395e7d2ff9fbd7cffc0b4c
This commit is contained in:
Sami Tolvanen 2016-09-01 15:58:35 -07:00
parent a5b02ff1ef
commit 433905f50e
1 changed files with 26 additions and 13 deletions

View File

@ -109,7 +109,8 @@ def AdjustPartitionSizeForVerity(partition_size, fec_supported):
Args:
partition_size: the size of the partition to be verified.
Returns:
The size of the partition adjusted for verity metadata.
A tuple of the size of the partition adjusted for verity metadata, and
the size of verity metadata.
"""
key = "%d %d" % (partition_size, fec_supported)
if key in AdjustPartitionSizeForVerity.results:
@ -121,27 +122,31 @@ def AdjustPartitionSizeForVerity(partition_size, fec_supported):
# verity tree and fec sizes depend on the partition size, which
# means this estimate is always going to be unnecessarily small
lo = partition_size - GetVeritySize(hi, fec_supported)
verity_size = GetVeritySize(hi, fec_supported)
lo = partition_size - verity_size
result = lo
# do a binary search for the optimal size
while lo < hi:
i = ((lo + hi) // (2 * BLOCK_SIZE)) * BLOCK_SIZE
size = i + GetVeritySize(i, fec_supported)
if size <= partition_size:
v = GetVeritySize(i, fec_supported)
if i + v <= partition_size:
if result < i:
result = i
verity_size = v
lo = i + BLOCK_SIZE
else:
hi = i
AdjustPartitionSizeForVerity.results[key] = result
return result
AdjustPartitionSizeForVerity.results[key] = (result, verity_size)
return (result, verity_size)
AdjustPartitionSizeForVerity.results = {}
def BuildVerityFEC(sparse_image_path, verity_path, verity_fec_path):
cmd = "fec -e %s %s %s" % (sparse_image_path, verity_path, verity_fec_path)
def BuildVerityFEC(sparse_image_path, verity_path, verity_fec_path,
padding_size):
cmd = "fec -e -p %d %s %s %s" % (padding_size, sparse_image_path,
verity_path, verity_fec_path)
print cmd
status, output = commands.getstatusoutput(cmd)
if status:
@ -204,7 +209,7 @@ def Append(target, file_to_append, error_message):
def BuildVerifiedImage(data_image_path, verity_image_path,
verity_metadata_path, verity_fec_path,
fec_supported):
padding_size, fec_supported):
if not Append(verity_image_path, verity_metadata_path,
"Could not append verity metadata!"):
return False
@ -212,7 +217,7 @@ def BuildVerifiedImage(data_image_path, verity_image_path,
if fec_supported:
# build FEC for the entire partition, including metadata
if not BuildVerityFEC(data_image_path, verity_image_path,
verity_fec_path):
verity_fec_path, padding_size):
return False
if not Append(verity_image_path, verity_fec_path, "Could not append FEC!"):
@ -250,7 +255,7 @@ def MakeVerityEnabledImage(out_file, fec_supported, prop_dict):
True on success, False otherwise.
"""
# get properties
image_size = prop_dict["partition_size"]
image_size = int(prop_dict["partition_size"])
block_dev = prop_dict["verity_block_device"]
signer_key = prop_dict["verity_key"] + ".pk8"
if OPTIONS.verity_signer_path is not None:
@ -281,10 +286,17 @@ def MakeVerityEnabledImage(out_file, fec_supported, prop_dict):
return False
# build the full verified image
target_size = int(prop_dict["original_partition_size"])
verity_size = int(prop_dict["verity_size"])
padding_size = target_size - image_size - verity_size
assert padding_size >= 0
if not BuildVerifiedImage(out_file,
verity_image_path,
verity_metadata_path,
verity_fec_path,
padding_size,
fec_supported):
shutil.rmtree(tempdir_name, ignore_errors=True)
return False
@ -355,12 +367,13 @@ def BuildImage(in_dir, prop_dict, out_file, target_out=None):
# verified.
if verity_supported and is_verity_partition:
partition_size = int(prop_dict.get("partition_size"))
adjusted_size = AdjustPartitionSizeForVerity(partition_size,
verity_fec_supported)
(adjusted_size, verity_size) = AdjustPartitionSizeForVerity(partition_size,
verity_fec_supported)
if not adjusted_size:
return False
prop_dict["partition_size"] = str(adjusted_size)
prop_dict["original_partition_size"] = str(partition_size)
prop_dict["verity_size"] = str(verity_size)
if fs_type.startswith("ext"):
build_command = ["mkuserimg.sh"]